(a) Field of the Invention
The present invention relates to a telephone system, such as a portable telephone system, having a telephone directory information and, more particularly, to a telephone system capable of retrieving and displaying items of names and telephone numbers stored as telephone directory information.
(b) Description of the Related Art
A telephone system is known which is provided with a telephone directory function for registering and storing items of names and corresponding telephone numbers, which are to be retrieved or searched by key operations. A user can select a desired name from the registered names of items by performing key operations while watching the display unit, and then make a telephone call to the telephone number of the selected item which is displayed on the display unit. A telephone directory function is particularly essential in the case of portable telephones (or or cellular phones), because carrying a separate telephone directory is troublesome and key operations are somewhat difficult in the portable telephone due to the smaller size of the keys.
As follows is a description of an example of a method for using the telephone directory function of a typical or conventional portable telephone system to select a name and make a call to that person.
First, the name of a person and the corresponding telephone number are registered and stored beforehand in the portable telephone as an item of the telephone directory information. Then, the user enters the first few characters of the name he wishes to call by using key operations, and searches the telephone directory information based on the entered character string. The portable telephone retrieves all the names from the registered telephone directory information, which include the few characters specified by the input character string, and displays those items of names and telephone numbers on the display unit. The user then uses a cursor to select the desired item for the name among the names displayed on the display unit and make a telephone call to the telephone number of the selected item.
In the manner as described above, the user can make a telephone call to the desired person without having to remember the telephone number, and furthermore without having to enter all the digits of the telephone number.
In the conventional telephone system as described above, the number of retrieved names obtained as a result of the retrieval differs depending on the input character string. Consequently, there are some occasions where the number of retrieved names including the entered character string is extremely large. In such a case, a large number of items of names are displayed on the display unit, and moving the cursor to select the desired item for the name among the large list of names takes a considerable length of time, which is undesirable to the users.
The number of names obtained from the retrieval can be reduced by entering a character string including a larger number of characters; however, this requires a large number of key operations, and thus another problem arises in which the key enter is annoying.
An object of the present invention is to provide a telephone system, such as a portable telephone system, in which a telephone number for a desired person can be easily selected from the information stored in a registered telephone directory.
The present invention provides, in one aspect thereof, a method for searching a desired item from stored information by using a character string sequentially input, the method including the consecutive steps of: (a) retrieving items from the stored information by using at least one first input character as a search key and counting a number of retrieved items; (b) comparing the number of the retrieved items against a first threshold; (c) displaying the retrieved items or the number of retrieved items on a display unit depending on the number of the retrieved items being smaller or larger than the first threshold; (d) again retrieving items from the stored information, if the number of retrieved items is displayed on the display unit in the step (c), by using a character string including the at least one first input character and at least one next input character as a search key and counting a number of the thus retrieved items; and (e) iterating the steps of (b) to (d) until the desired item is displayed on the display unit in the step (c).
The present invention also provides, in another aspect thereof, a telephone system including:
a storage unit for storing information: a retrieval section for retrieving items from the information stored in said storage unit by using a first input character in a character string as a search key; a counter for counting a number of items retrieved by said retrieval section; a comparator for comparing the number counted by said counter against a first threshold to generate a display signal or the retrieval signal depending on the number counted by said counter being smaller or larger than the threshold; and a display unit for displaying thereon the items upon generation of the display signal and displaying the number counted by the counter upon generation of the extraction signal, said retrieval section retrieving at least one item from the information by using the first input character and a next input character after generation of the retrieval signal.
In accordance with the method and the telephone system of the present invention, the user does not have to use a specific operation to reduce the number of retrieved items except for inputting a next character in the character string.
The above and other objects, features and advantages of the present invention will be more apparent from the following description, referring to the accompanying drawings.